Brewzilla 35l gen 4... wort level rising

[Barone]

Wort level rising ,pump stops working...what could it be?
Thanks

 

[peterpiper]

Is that while mashing?
Then probably a stuck mash, where pump's then drained all liquid from outside and under malt pipe, and airs entered pump.
Had that happen on BZ gen 3, when using pro-pipe base (no overflow - like gen 4) and a big (wheat) grain bill. Needed good stir up of malts at bottom to get pipe draining again.

Does wall of your Malt Pipe have perforations towards the bottom (like the GF40)?
I'm wondering if this was later mod, to help prevent a stuck mash. BrewKegTap say the ones they (now) sell, have these extra holes. But early gen 4 reviews all look to be solid wall pipes (like gen 3).

 

[Barone]

Is that while mashing?
Then probably a stuck mash, where pump's then drained all liquid from outside and under malt pipe, and airs entered pump.
Had that happen on BZ gen 3, when using pro-pipe base (no overflow - like gen 4) and a big (wheat) grain bill. Needed good stir up of malts at bottom to get pipe draining again.

Does wall of your Malt Pipe have perforations towards the bottom (like the GF40)?
I'm wondering if this was later mod, to help prevent a stuck mash. BrewKegTap say the ones they (now) sell, have these extra holes. But early gen 4 reviews all look to be solid wall pipes (like gen 3).

Yes...it happens when mashing...there are perforations on the side...at the bottom...without wheat...ratio 4:1 water grain

 

[peterpiper]

Maybe worth reducing pump flow a bit, so flow balances pipe drain rate. Increase flow till level just starting to rise, then back it off a bit.

I use recirculation pipe valve (on gen 3). Gen 4 also has electronic pump control, that works by varying on/off ratio, but some reports say using that can allow grain to backsyphon through sparge pipe.

This post (from page 23ish) has quite a bit on bz35 gen4 blockages
Brewzilla Gen4 Discussion/Tips Talk
(insert hyperlink not working today).

 

[user 49381]

Wort level rising ,pump stops working...what could it be?
Thanks

I got that on my first brew. Second brew I kept an eye out for it. It's caused by compaction of the mash whilst recirculating. All the water sits on top and there's just air underneath. Removing the mash top plate and a stir got things moving again.
I'm making thee changes from now on.
First, I'm not using that mash top plate they supply. It seems to sink, trap debris and help to compact the mash. I'll use it at sparge time to help avoid channeling.
Second, I'm going to reduce the flow rate of the recirculation.
Third, and I suspect most important, I'm going to increase the roller gap on my mill from 0.85mm to 1.2mm. the fine milling was great on my old 3 vessel kit but friends with all in one systems recommend going more coarse.